Oscilliameter.



H; SHOEMAKER.

OSGILLIAMETBR.

APPLIOATION FILED DB0.11, 190e.

932,819. Patented Aug. 31, 1909.

ms A Tran/Ex `SAJES PATENT HAIBY BHGEIKER, 0F JERSEY CITY, NEW JERSEY, ASSIGNOB T0 GRAPH CONSTRUCTION OOIPANY,

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onirica.

mmmmenmnm- A COBPORATIGN GFNIW Your.

Patented Aug. 31, 1909.

Appuauon mea December 11, 190e. semi No. 347,271.

To. ell, whom it may concern:

Be it known that I, HARRY SIIOEMAKER, a citizen of the United States, residing at. Jerse f City, in the county of Hudson and State o' New Jersey, have invented a new and use# fnl Uscillian'ieter, of which the following is a specification.

vMy invention relates to apparatus for making various determinations in the art of signaling by electroradiant energy, or in kin-4 dred arts. l

It is the object of my invention to provide means for determining the frequency or the wave length of eleetroradiant energy, which means may serve to determine such factors of either a transmitting or receiving apparatus; and it is also the object of my invention that such means shall serve as a standard for producing at will electroradiant energy of a definite frequency or Wave length. Such apparatus serves as Well as a test instrument for adjusting transmitting apparatus, so it shall emit electroradiant energy of definite frequency or Wave length; and similarly to adjust the receiving apparatus, so that it shall be in condition to respond selectively to received energy of definite frequency or wave length.

My invention resldes also in a form of deteetor or Wave-responsive device suitable for use in connection with such apparatus and particularly adaptable for mounting upon the instrument case.

My invention resides also in features hereinafter pointed out and described in the claims.

For an illustration of a form my invention may take, reference isto behad to the accompanying drawing, in Which-z Figure 1 is a plan view of the instrument. Fig. 2 is a vertical sectional View, partly in elevation, ofthe detector or wave responsive device. Fig. 3 is a Side elevation of the apparatus shown in Fig. 1 Fig. 4 is a diagrammatic view illustrating the circuit connections.

In the drawing, l is a top, of insulating material, of a box 2 containing a variable wndenser, adjusted by means of the rotatable handle 3, and a condenser of constant capacity hereinafter referred to. A. pointer 4t, secured. to the handle 3 or rotatable member of the variable condenser, passes over the scale 5, grilduated in degrees, .or if desired, in frequencies or wave lengths. The binding posts 6 and Z form terminals of the variable condenser and serve for connection to external apparatus for certain pur oses, as hereinafter described, A socket or a small incandescent llamp is also provided in the top 1, the screw threaded terminal' is shown at 8 and the button terminal at 9. 111

Lcert-ain instances a small incandescent lam is screwed into this socket, and for other purposes a short circuiting lug is screwed into the socket, so that the lfminals 8 and E) are connected to each other Without any intervening resistance. Binding posts 10 and 1l serve for connectionbf a telephone receiver or any other suitable indicating instrument. A s ark gap is also provided and has as termina s the stationary platinum 12 spring 22., which bears at its upper end upon the metallic cap 23 on the up er end of a glass` tube 24. In the. lower en l of the glass tube is sealed a small conductor, als a carbon. filament, or as a platinum, tantalum, copper or other suitable wire. electrically connected with the cap. 23,. The

Such conductor is diameter of such, filament or wire may be .0.01 of an inch, more or less, and may even be as large as .005l of an inch, or more. The

glass and conductor are ground off, sor-,that the end section only of the conductor lslexs posed. The glass tube enters a suitablev openingI in the rubber or other plug 25, screw threaded into the inside of the metallic cup 2.6. The plug 25 is recessed on its lower end and shouldered, a cloth, paper or other material, 27, impregnated With sulfurie or other acid, or with alkali, or with any suitable chemical material which will serve as a cell excitant, is confined in said recess'upon the -top of a. block or rod 28 of zinc, iron, or other material, differently 1o- `able capacity intervening in series.

cated in the galvanic scale from the conductor sealed in the glass tube 24. By

screwing down the plug 25 the zinc or other rod 28 is held against the bottom of the cup 26, making electrical contact therewith.

The platinum or other conductor sealed in the tube 24 along with the amalgamated zinc or other rod 28, form the elements of a primary cell whose excitinfr-mate1'1al, acid, alkali, or salt, is supported=` 1n the cloth or paper sheet 27. The cell elements do not., therefore, Contact with a free mass of liquid.

The cup 26 has a tapering stem 29, which is convenientlyl inserted into the tapered socket piece 30, o f meta-l, fastened by the nut 31. Thus, the entire primary cell detector may be readily removed or inserted, and when inserted makes electrical contact with the post 21, and, on the other hand, with the' socket 30 or nut 31.

Referring to Fig. 4, the reference characters indicate the same elements described in connection with Figs. 1 to 3 inclusive. VK represents the variable condenser adjusted by rotating the handle 3 and located Within the box 2. One armature of this condenser is connected by conductor 32 with the clamp 16. The other armature is connected by conductor 33 with the other clamp 17 the spark gap 13, 14 and lamp socket 8, 9 intervening in series. To the clamps 16 and 17 is connected the inductance element 34 here shown as a single loop of conductor, but which may be a coil of conductor or conductor disposed in any suitable form. A telephone or other suitable indicating instrument T is connected to the binding posts 10 and 11 which are in turn connected to the opposite elements of the primary cell detector 24, 27, 28. This detector or waveresponsive device is connected across the inductance element 34, a condenser C of suit- Obviously the condenser C and the Wave-responf sive device are connected in shunt to the vavriable condenser VK as well, when the spark gap is closed up and the lamp socket 8, 9 short circuited by the plug heretofore mentioned. l

lVith a given inductance element 34, and with the scale 5 divided into degrees, the apparatus may be calibrated by causing waves of known frequency or length to impinge upon the induct-ance 34' or other suitable conductor attached to the apparatus. For this calibration the spark gap 13, 14 is closed so that 13, 14 are in metallic contact, and the socket 8, 9 short circuited by inserting the short circuiting plug. Then by varying the condenser VK by rotating the handle 3 until a maximum response is heard or indicated in the telephone or other instrument T. a point on a calibration curve or table is found. And by repeating the process for other known wave lengths or frerange of theinstrument may be determined.

. For securing' the waves of known frequency or lengt-h, Hertzs method of producing waves on straight wires may be em loyed, or on such wire as can be measured irectly in any suitable unitof length, as the foot. or meter.

With a given inductance element 34, the4 instrument. may be calibrated to read directly in frequencies or wave lengths on the scale 5. lVhen the instrumenthas once been calibrated it may be ut to varioususes, several of which are as ollows: To determine the frequency orlength of electro-radiant energy waves: The waves to be measured are caused to impinge upon the conductor 34 or any other conductor suitably. communicating with the instrument. Then'with the spark gap closedand the lam socket short circuited, the handle 3 is adjusted until a maxiy.

mum response is had in the telephone T connected'tothe detector or wave-responsive device. Vith the intervening condenser C of suitable capacity the region of maximum response is very sharply defined and within verynarrow limits, so that the wave-responsive-device or detector and telephone may be used to great advantage when measuring very faint waves such as received at a receiving station from a distant transmitt-er. Vhen the point of maximum response is determined the number of degrees on the scale 5 is read olf as indicated by the pointer 4.and then by referring to the curve or table the frequency of the Wave is read otf.- Or if the scale 5 is graduated directly Cil in frequencies or wave lengths, the result is read directly from the sca e 5 at the oint indicated by the ointer 4. Thus, i the wave length of a istant transmitter is desired, the aerial conductor or receiving circuit may be connected to the posts 16 and 17 or 6 and 7 and then the adjustment of the condenser VK made as above described and the result read off. The extremely sensitive detector with the telephone makes the reading of the extremely'weak waves possible, and as before stated, the circuit arrangements here shown are such as to give very sharply defined readings. Or when the transmitter is near at hand, the Wave-responsive device and telephone may be omitted and with the spark gap 13, 14 closed, a small incandescent-.lamp is screwed into the socket 8, 9. Then the handle 3 is adjusted until the lamp comes to its greatest brilliancy. Then length: For this'purpose the instrument. acts as a standard transmitter of low power, just as a. standard cell s`er\'es as a standard of electromotive force. The sprin f 22 may be moved to one side and the tu e 24 withdrawn, as may be also, if desired, the-cup 26. With the telephone detached, the lam socket 8, 9 short circuited, and the spar: gap 13, 14 open, the instrument is in condition to produce waves of definite frequencies or lengths. The pointer 4 is moved to that part on the scale 5 corresponding with t-he frequency or wave length desired. Then the secondary of a small induction coil is connected to the posts (i and 7 and the screw 13 adjusted until a suitable spark passes. Then a wave of the desired frequency or length is generated in the circuit- VK, 13, 14, and 34, the conductor 34 and the connecting conductors serving` as radiator. When so used to produce waves of`definite length or frequencies, receiving apparatus may be adjusted to respond selectively to that particular frequency or wave length by bringing the wave producing instrument suiiiciently close to the aerial conductor or receiving circuit, as, for example, to within a distance of a meter or two or three meters, or more or less.

In place of connecting and disposing the inductance element 34 upon the outside of the box 2, it may be contained within the box and may be suitably divided into a plurality of sections with a switching means for connecting in any or all of the said sections.

What. I claim is:

l. In a combined wave meter and wave producer, the combination with a condenser, of an inductance, said condenser and inductance being common to said wave meter and to said wave producer, a s ark gap, a wave-responsive device, means or associating either said spark gap or said wave-responsive device with said condenser and inductance, and a calibration scale for indicating the natural, period of the combine condenser and inductance.

2. In an instrument of the character described, the combination with a variable conde'nser, of an inductance element, a scale for indicating the natural period of the combined condenser and inductance, and an incandescent lamp in series with said condenser and inductance as an indicating means.

3. In an instrument of the character described, the combination with a variable condenser, of an inductance element, a scale for indicating the natural period of the combined condenser and inductance, a spark gap and lamp serially connected with said condenser and inductance, and means for short circuiting either the spark Agap or lamp.

4. In a wave meter, the combination with a varlable condenser, of an inductance element, a scale for indicati 'the natural period of 'the combined con enser and inductance, a wave-responsive device in shunt with said condenserl and inductance, and an indicating instrument associated with said waveresponsive device, wherebyI the fre- (uency or wave length of feeble electroraiant energy may be determined. In an electrical measuring instrument of the character described, the combination with a. variable condenser, of an inductance element, a scale for indicating the natural period of said combined condenser and inductance, a condenser and a wave-responsive device seriallyconnected across said variable condenser, and an indicating instrument associated with said Wave-responsive device, whereby the wavelength or frequency of feeble electroradia-nt energy may be determined.

In an electrical measuring instrument of the character described, the combination With a variable condenser, of an inductance element, a scale for indicating 'the natural period of the combined condenser and inductance, a condenser and a detector serially connected across said inductance and condenser, and an indicating instrument associated with said detector, whereby the Wave length or frequency of feeble electroradiant energy may be determined.

7'. In a combined wave meter and wave producer, the combination with a condenser, of an inductance, said condenser and inductance serving both for the Wave meter and for the wave producer, a spark gap, a detector, and means for bringing either the spark gap or the detector into operative relation W1th saidcondenser and inductance.

8. In an instrument of the character described, the combination with a condenser, of an inductance, means for adjusting the natural period of the combined condenser and inductance, a scale for indicating the4 natural period, a spark gap and a lamp associated with said condenser and inductance, and means for short circuiting either said spark gap. or lamp.

9. In a wave meter, the combination with a condenser, of an inductance, a scale for indicating the natural period of the combined condenser and inductance, and a sensitive detector connected in derivation with said condenser and inductance.

10. In a wave meter, the combination with a condenser, of an inductance, a scale for indi'catin the natural period of the condenser and i'nuctance, and a sensitive detector consuming relatively small energy connected in derivation with said condenser and inductance.

11. A wave meter comprising a condenser and inductance, a scale for indicating the natural period of the combined condenser and inductance, and a sensitive detector requiring no local battery and consuming relatively small energy connected in derivation with said condenser and inductance.

12. A wave meter comprising a condenser and inductance, means for varying the natural period, and a scale. coperating with said means for indicating the natural period of the combined condenser and inductance, a wave-responsive vdevice consisting of means for producing current under the influence of lilgh frequency oscillations, and a condenser intervening between said wave-responsive device and said condenser and inductance.

- 13. A wave meter comprising a condenser and inductance, a casing, a cover therefor, a wave-responsive device associated with' said condenser and inductance, and a plug receptacle supporting said wave-responsive rdeconsuming relatively small enerjy and requiringno local battery connected in derivation with said condenser and inductance.

` In testimony whereof I have hereunto affixed my signature in the presence of two subscribing witnesses.

HARRY SHOEMAKER.

Witnesses:

JAMES M. SAWYER, A. D. KNEUPER.

from adjustment, and .a sensitive detector' 

